Businesses or other entities having a need for volume printing typically purchase a production printer. A production printer is a high-speed printer used for volume printing, such as 100 pages per minute or more. The production printers are typically continuous-form printers that print on paper or some other printable medium that is stored on large rolls.
A production printer typically includes a localized print controller that controls the overall operation of the printing system, a print engine (sometimes referred to as an “imaging engine” or as a “marking engine”), and a dryer. The print engine includes one or more printhead assemblies, with each assembly including a printhead controller and a printhead (or array of printheads). An individual printhead includes multiple tiny nozzles (e.g., 360 nozzles per printhead depending on resolution) that are operable to discharge ink as controlled by the printhead controller. The printhead array is formed from multiple printheads that are spaced in series along a particular width so that printing may occur across the width of the medium. The dryer is used to heat the medium and ink to dry the ink onto the medium.
For drop on demand print engines, drops of ink are ejected as needed to mark the medium with ink. During times of inactivity, ink within the nozzles of the print engine can begin to dry, which may clog or otherwise disturb the flow pattern when the nozzles resume ejecting ink drops. Thus, algorithms are designed to generate flush patterns to eject ink drops through the nozzles of the print engines to prevent this from occurring. This activity occurs during the actual job printing process, as nozzles may vary in activity during the printing process. The algorithms may utilize various criteria for generating flush patterns while printing the job, such as the amount of time one or more of the ink jet nozzles has been inactive, etc. The flush patterns may be printed onto non-used portions of the medium as a line or other pattern, or may be dispersed within portions of the medium that are marked based on print data for the job. However, it may not be desirable or possible to reserve blank portions of the medium for printing the flush patterns during printing of the job. Further, printing the flush pattern within the printed data for the job may reduce the quality of the printed output for the data.